Landry Breuil (..landry@) just committed a fix to devel/nspr for the Netscape Portable Runtime, Mozilla products use this library for a wide variety of platform-specific tasks such as memory allocation and networking.

A bug was found that limited amount of memory Firefox was capable of using for page caches, it slowed down rendering quite a bit.

So for those snapshot/current followers, make sure you have nspr-4.8.6p0 or higher.. when it's available on the mirrors, or just build it.

Installing this update doesn't require that you recompile Firefox or Thunderbird.